• ETRI Journal
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• v.38 no.2
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• pp.260-264
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• 2016

We report on highly efficient blue, orange, and white phosphorescent organic light-emitting diodes consisting only two organic layers. Hole transporting 4, 4,' 4"-tris (N-carbazolyl)triphenylamine (TcTa) and electron transporting 2-(diphenylphosphoryl) spirofluorene (SPPO1) are used as an emitting host for orange light-emitting bis(3-benzothiazol-2-yl-9-ethyl-9H-carbazolato) (acetoacetonate) iridium ((btc)2(acac)Ir) and blue light-emitting iridium(III)bis(4,6-difluorophenyl-pyridinato-N,C2') picolinate (FIrpic) dopant, respectively. Combining these two orange and blue light-emitting layers, we successfully demonstrate highly efficient white PHOLEDs while maintaining Commission internationale de l'eclairage coordinates of (x = 0.373, y = 0.443). Accordingly, we achieve a maximum external quantum, current, and power efficiencies of 12.9%, 30.3 cd/A, and 30.0 lm/W without out-coupling enhancement.

• The Journal of Korean Physical Therapy
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• v.10 no.2
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• pp.97-104
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• 1998

The Purpose of this study was ta investigate the change of bone density by Partial weight bearing and non-weight bearing exercise. Twelve female volunteers in good health (between 20 and 30 years of age) were studied as subjects. Subjects were divided into three groups; an experimental group 1(n =4 swimming group), group 2(n = 4 bicycle group) and control group=4. Before and after 11weeks(five times a week), the subjects were examined for change of bond density using a dual energy X-ray absorptiometry. The results were summarized as fellows T . There was increase in bone density of femoral neck in the group that swam but there was no difference in lumbar, femoral neck and femoral ward's triangle region (P<0.05) 2. There was increase in hone density of femoral ward's triangle in the group that swam but there was no difference in lumbar, femoral neck and femoral ward's triangle region(P<0.05) 3. After a aerobic exercise by partial weight bearing and non-weight bearing , there was no difference in the part of excessive muscle's exercise but there is the increase of the bone density in figures.

• Textile Coloration and Finishing
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• v.3 no.1
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• pp.17-24
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• 1991

Polyesteramide(PEA) has been synthesized with different molar ratio of 6-aminocaproic acid(ACA) and oligo butylene terephthalate(OBT) prepared from Dimethyl terephthalate(DMT) and 1, 4-butanediol(BD) by the melt polymerization. Oligomer and polymer molecular structure were characterized by IR spectra, H'-NMR spectra. Also the thermal properties were examined by thermogravimetric analysis(TGA) and differential scanning calorimetry(DSC). DSC and TGA results exhibited that the$ T_m$ s were detectable in the vicinity of $170-220^{\circ}C$ and the Ta's were detectable in the vicinity of $380-390^{\circ}C$ . X-ray diffraction analysis results show that the synthesized polyesteramide has high degree of crystallinity.

• Korean Journal of Materials Research
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• v.11 no.9
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• pp.802-809
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• 2001

Electroplating is an attractive alternative deposition method for copper with the need for a conformal and conductive seed layer In addition, the Cu seed layer should be highly pure so as not to compromise the effective resistivity of the filled copper interconnect structure. This seed layer requires low electrical resistivity, low levels of impurities, smooth interface, good adhesion to the barrier metal and low thickness concurrent with coherence for ensuring void-free fill. The electrical conductivity of the surface plays an important role in formation of initial Cu nuclei, Cu nucleation is much easier on the substrate with higher electrical conductivities. It is also known that the nucleation processes of Cu are very sensitive to surface condition. In this study, copper seed layers deposited by magnetron sputtering onto a tantalum nitride barrier layer were used for electroplating copper in the forward pulsed mode. Prior to electroplating a copper film, the Cu seed layer was cleaned by plasma H$_2$ and $N_2$. In the plasma treatment exposure tome was varied from 1 to 20 min and plasma power from 20 to 140W. Effects of plasma pretreatment to Cu seed/Tantalum nitride (TaN)/borophosphosilicate glass (BPSG) samples on electroplating of copper (Cu) films were investigated.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.6
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• pp.1228-1233
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• 2004

Character of the technology that is going to lead the next generation convergence network which has been discussed recently can be represented by Integrating and Convergence. As Wireless Telecommunication and Broadband Transport Technology make rapid progress for several years, and those of two important technical advance, Integrating, Convergence will combine with the latest terminal technology. so it becomes a big issue of utmost importance. This paper, therefore, investigates the network deployment strategies and relating technology toward Broadband Convergence Network(BcN) and makes a survey of up-to-date technique based on Telecom Service businesses which have been required.

• Journal of Multimedia Information System
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• v.6 no.2
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• pp.107-118
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• 2019

This paper deals with actual optical data from rural as well as urban areas in a nationwide study captured with Fisheye cameras. Simultaneously data was collected (of the receiving power density) from the mobile communications satellite N-STAR. The visibility of the satellite is easily determined by checking the value of the pixels in the binarized fisheye image of its position. The process of determining the visible satellite is automatically performed. Based on the analyses of the field data measured in Japan, we are expecting HEOs (Highly inclined Elliptical Orbiters) that would reduce blockage in the extreme northern region of Wakkanai City well as in the most crowded urban area, in Tokyo Ginza. In case of HEOs operation, the elevation angle will improve from 37 with N-STAR GEO to 75 degrees. HEOs could replace 5G/Ka-band or support in rural areas where broadband circuit is not available. We are proposing combination operations with HEOs and 5G/Ka-band to solve blockage problems, because HEOs can keep line-of-sight propagation with high elevation angle for long duration. In such operations, the communications profile on the vehicle based on actual optical data will be very useful to predict blockages and to select/switch a suitable circuit.

• Journal of the Korean Magnetics Society
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• v.13 no.2
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• pp.53-58
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• 2003

Annealing effects of exchange bias fields ($H_{2ex}$(top), $H_{lex}$ (bottom)) on composite type NiFe/[FeMn/Mn]$_{80}$/NiFe multilayers have been studied. Three samples with ultra-thin Mn inserted layers on glass/Ta(50 $\AA$)/NiFe(150 $\AA$)/[F $e_{53}$M $n_{47}$(1.25 $\AA$)/Mn(0 $\AA$, 0.11 $\AA$, 0.3 $\AA$)]$_{80}$/NiFe(90 $\AA$)/Ta(50 $\AA$) were prepared by ion beam sputtering. The average x-ray diffraction peak ratios NiFe(111) of FeMn (111) fcc textures for the Mn inserted total thicknesses of 0 $\AA$, 9 $\AA$, and 24 $\AA$ were about 0.65, 0.90, and 1.5, respectively. For the sample without Mn inserted layer, the $H_{2ex}$ of 260 Oe up to 300 $^{\circ}C$ disappeared at 350 $^{\circ}C$. For two multilayer samples with ultra-thin Mn layers of 0.11 $\AA$ and 0.3 $\AA$, the $H_{2exs}$ of 310 Oe and 180 Oe up to 300 $^{\circ}C$ endured of 215 Oe and 180 Oe at 350 $^{\circ}C$, respectively. The $H_{ex}$ (bottom)s of three samples decreased from 100 Oe to 70 Oe up to 250 $^{\circ}C$, while these values increased beyond 300 $^{\circ}C$. This observation can be attributed to less diffusive path of Mn atoms in bottom NiFe than top NiFe layer. The top and bottom coercive fields slightly varied about 5 Oe∼10 Oe. From these results, we could obtain the enhancement of exchange coupling intensity and thermal stability by an ultra-thin Mn inserted layer on NiFe/[FeMn/Mn]$_{80}$/NiFe Multilayers.

• Biomolecules & Therapeutics
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• v.18 no.3
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• pp.280-285
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• 2010

Glycosaminoglycans (GAGs) and chitosan have been used as matrix materials to support the dermal part of skin equivalent which is used for both pharmacological and toxicological evaluations of drugs potentially used for dermatological diseases. However, their biological roles of GAGs and chitosan in the skin equivalent are still unknown. In the present study, we evaluated whether GAGs and chitosan directly affect keratinocyte stem cells (KSCs) and their transit-amplifying cells (TA cells). Among supporting matrix materials, chitosan significantly increased the number of ${\alpha}6$ $integrin^{high}/CD71^{high}$ human keratinocyte TA cells by 48.5%. In quantitative real-time RT-PCR analysis, chitosan significantly increased CD71 and CD200 gene transcription whereas not ${\alpha}6$ integrin. In addition, the level of the gene transcription of both keratin 1 (K1) and K10 in the chitosan-treated human keratinocytes was significantly lower than those of control, suggesting that chitosan inhibit keratinocyte differentiation. We also found that N-acetyl-D-glucosamine (NAG) and $\beta$-(1-4)-linked D-glucosamine (D-glc), two components of chitosan, have no effect on the expression of CD71, K1, and K10, suggesting that each monomer component of chitosan is not enough to regulate the number of epidermal keratinocyte lineage. Conclusively, chitosan increases keratinocyte TA cell population which may contribute to the cellular mass expansion of the epidermal part of a skin equivalent system.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.1
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• pp.7-15
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• 2004

The ferroelectric SBT thin films as a material of capacitors for non-volatile FRAMs have some problems that its remanent polarization value is relatively low and the crystallization temperature is quite high abovc 80$0^{\circ}C$. Therefore, in this paper, SBTN solution with S $r_{0.9}$B $i_{2.1}$T $a_{1.8}$N $b_{0.2}$$O_{9}$ composition was synthesized by sol-gel method. Sr(O $C_2$ $H_{5}$)$_2$, Bi(TMHD)$_3$, Ta(O $C_2$ $H_{5}$)$_{5}$and Nb(O $C_2$ $H_{5}$)$_{5}$ were used as precursors, which were dissolved in 2-methoxyethanol. SBTN thin films with 200 nm thickness were deposited on Pt/Ti $O_2$/ $SiO_2$/Si substrates by spin-coating. UV-irradiation in a power of 200 W for 10 min and rapid thermal annealing in a 5-Torr-oxygen ambient at 76$0^{\circ}C$ for 60 sec were used to promote crystallization. The films were well crystallized and fine-grained after annealing at $650^{\circ}C$ in oxygen ambient. The electrical characteristics of 2Pr=11.94 $\mu$C/$\textrm{cm}^2$, Ps＋/Pr＋=0.54 at the applied voltage of 5 V were obtained for a 200-nm-thick SBTN films. This results show that 2Pr values of the UV irradiated and rapid thermal annealed SBTN thin films at the applied voltage of 5 V were about 57% higher than those of no additional processed SBTN thin films. thin films.lms.s.s.

• Preventive Nutrition and Food Science
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• v.1 no.2
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• pp.203-207
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• 1996

Methanol extract of dried persimmon leaves was refractionated using hexane, chloroform, ethylacetate, n-butanol aqueous fractions. Among these chloroform fraction showed the highest inhibition rate on the mutagenicities of aflatoxin B₁(AFB₁) and 3,2' -dimethyl-4-amino-bipheny1(DMAB) in Salmonella typhimurium TA 100. Chloroform fraction was further fractionated into eight fractions by silica gel column chromatography and thin layer chromatography(TLC). The fraction 5 on TLC exhibited the highest antimutagenic activities in AFB₁and DMAB. 2,4-Decadienal, dihydro-4-methyl-2(3H)-furanone, hexanoic acid 1,4-bis(1-methy1 ethy1)benzene, heptanoic acid, phenol, octanoic acid, nonanoic acid and benzoic acid were tentatively identified from this antimutagenic fraction by GC-MS.